This invention relates to a solenoid valve having the portion of the valve, which opens or closes the pressure fluid lines, between the side exposed to the atmosphere and that side subject to the force of the fluid pressure, sealed to the housing in which the valve is mounted.
A solenoid valve of this type is generally installed in a brake pressure control system of an anti-locking brake system to avoid locking in a sudden braking situation, or in a traction control system to avoid spinning of the wheels. As shown in FIG. 8 in such a system, several solenoid valves b are incorporated in a housing which comprises a portion of an anti-locking braking system or traction control system.
In this conventional device, each solenoid valve is set within a respective cavity c of housing a, wherein a cover d affixed to the housing with bolts fits over that side of the solenoid valve exposed to the atmosphere.
The pressure of the fluid acting on the solenoid valve b presses the valve in the direction of the atmosphere, necessitating a cover d and bolts e formed from material of sufficient strength to withstand the pressure. This material adds to the high cost, weight, and bulk of the cover. Additionally, when the brake pressure increases, the cover d is pressed against the solenoid valve b causing elastic deformation wherein the solenoid valve b moves in the direction of the atmosphere; when the pressure decreases the valve reverses in the other direction. Consequently, the rubber seal f attached to the solenoid valve b is subjected to pressure and slides between the housing a and the solenoid valve b. This causes the rubber seal f to be easily subject to wear and tear, reducing the reliability of the seal. Further, when the pressure increases, extra fluid in an amount corresponding to the distance the solenoid valve b slides is consumed; whereby if the solenoid valve is used in the hydraulic brake system of a vehicle, the brake pedal stroke increases.